Saving sweet pea seeds is an easy way to continue growing your favorite flowers year after year! Learn how to collect sweet pea seeds in fall to plant again in spring!
These vines pumped out hundreds of flowers over the summer. But by September, they were looking pretty tired. The bottom sections were dry and turning brown, the stems were getting shorter and the plants were starting to succumb to powdery mildew.
So I decided to stop picking and deadheading the flowers and allow them to go to seed. Once the pods dried, I could save the sweet pea seeds and enjoy my favorites again next spring!
Watch the video below for a quick overview of the process, then read on for more details.
This post contains affiliate links for your convenience. Purchases made through these links may earn me a small commission at no additional cost to you.
When to harvest sweet pea seeds
Knowing when to harvest sweet pea seeds is crucial for ensuring you collect viable, healthy seeds for the next growing season.
It can take a few weeks after the sweet pea flowers have bloomed and died back to form a mature seed pod. It starts off looking just like a sugar snap pea, but don't eat it because sweet peas are toxic! The seeds are still forming at this green stage, and aren't ripe yet.
The pods should be dry, brittle, and brown. When you press them gently, they should feel firm to the touch, which is a good indicator that the seeds inside are mature enough to harvest.
The photo below shows the various stages of a sweet pea seed pod once it's ripe. I recommend cutting them off the vine with the stem intact, rather than yanking them. This prevents damage to the pods and keeps the seeds inside until you're ready to harvest them.
If you wait too long, the pods might split open, scattering the seeds everywhere like the pod in the middle. The pod on the right was left on the vine during a week of heavy rain and turned black and moldy.
Drying and Curing Sweet Pea Seeds
Properly drying your sweet pea seeds is a crucial step that ensures they'll be viable for future planting. If seeds are stored with excess moisture, they can easily rot or mold, rendering them useless.
Spread the whole pods out on a flat surface like a paper towel, tray, or mesh screen, and let them sit in a dry, well-ventilated area for about a week. You can also leave them in a small paper bag, as long as you keep it open to allow moisture to evaporate.
You'll know your seeds are adequately dried when the pods become brittle and easy to crack open. If it breaks cleanly, the seeds inside are likely ready for the next stage: separating them from the pods.
Separating Sweet Pea Seeds from the Pods
Now that your sweet pea seed pods are all dried up, it's time to extract the seeds. It's super easy!
First, remove the stem. Then gently apply pressure along the seam until it cracks open.
The pods are very brittle, and can easily snap apart, revealing the seeds inside.
Carefully separate the two halves and pop out the seeds!
As you're doing this, be sure to sort the seeds, setting aside any that look discolored, shriveled, or otherwise damaged. Healthy seeds are plump and round with a uniform color.
If you have a lot of pods to process, or you find that your seeds are flying everywhere, here are a few tricks to speed up harvesting.
Some people find that using a rolling pin helps crack open the pods more easily. Just place the dried pods inside a cloth bag or wrap them in a towel, then gently roll over them. Discard the broken pods and sort out the seeds.
You can also leave the pods for a few weeks in a warm, dry area inside a mesh bag. Many of the pods will split apart on their own, and you can shake the bag to separate the seeds.
Storing Sweet Pea Seeds
Paper envelopes work well for storing seeds. Be sure to write the plant name, variety and date collected on the front. You can also use glass jars if you have lots of seeds, especially for bulky ones like these.
Keep your seeds in a cool, dark place where the temperature and humidity are relatively stable. I keep mine sorted in this photo organizer, which is then stored in our basement.
Under ideal storage conditions, sweet pea seeds can remain viable for three years or more. However, it's generally a good idea to use them within the first year for the best germination rates.
Collecting sweet pea seeds can save you money and give you a head start on next year's garden. One pod can yield as many seeds as a single packet, which can cost up to $5! It also ensures that you can continue growing your favorite varieties for years to come!